MCQ in Strength of Materials Part 6 | ECE Board Exam

This is the Multiple Choice Questions Part 6 of the Series in Strength of Materials as one of the General Engineering and Applied Sciences (GEAS) topics. In Preparation for the ECE Board Exam make sure to expose yourself and familiarize yourself with each and every question compiled here taken from various sources including past Board Questions in General Engineering and Applied Sciences (GEAS), Strength of Materials Books, Journals, and other Strength of Materials References. (Note: Rectilinear Translation and Centrifugal Force questions and answers added)

Continue Practice Exam Test Questions Part 6 of the Series

⇐ MCQ in Strength of Materials Part 5 | ECE Board Exam

Choose the letter of the best answer in each question.

251. The flywheel of a puncher is to be brought to a complete stop in 8 seconds from a speed of 60 revolutions per minute. Compute the number of turns the flywheel will still make if its deceleration is uniform.

A. 5 turns

B. 3 turns

C. 4 turns

D. 6 turns

252. What is the speed of a synchronous earth’s satellite situated 4.5 x 10^7 m from the earth?

A. 11,070.0 kph

B. 12,000.0 kph

C. 11,777.4 kph

D. 12,070.2 kph

253. A rotating wheel has a radius of 2 feet and 6 inches. A point on the rim of the wheel moves 30 feet in 2 sec find the angular velocity of the wheel.

A. 2 rad/s

B. 4 rad/s

C. 5 rad/s

D. 6 rad/s

254. A turbine started from rest to 180 rpm in 6 minutes at a constant acceleration. Find the number of revolutions that it makes within the elapsed time.

A. 500

B. 540

C. 550

D. 630

255. A flywheel is 15 cm in diameter accelerates uniformly from rest to 500 rpm in 20 seconds. What is its angular acceleration?

A. 2.62 rad/s^2

B. 3.45 rad/s^2

C. 3.95 rad/s^2

D. 4.42 rad/s^2

256. A boy tied a 60 grams stone to a string which he rotated to form a circular motion with a diameter of 1000 mm. compute for the pull exerted on the string by the stone if it got loose leaving at a velocity of 25 m/sec.

A. 120 N

B. 100 N

C. 150 N

D. 135 N

257. A man keeps a 1 kg toy airplane flying horizontally in a circle by holding onto a 1.5 m long string attached to its wing tip. The string is always in the plane of the circular path. If the plane flies at 10 m/sec, find the tension in the string.

A. 28 N

B. 15 N

C. 67 N

D. 18 N

258. An automobile travels on a perfectly horizontal, unbanked circular track of radius R. The coefficient of friction between the tires and track is 0.3. If the car’s velocity is 15 m/s, what is the smallest radius it may travel without skidding?

A. 68.4 m

B. 69.4 m

C. 71.6 m

D. 76.5 m

259. A hi-way curve has a super elevation of 7 degrees. What is the radius of the curve such that there will be no lateral pressure between the tires and the roadway at a speed of 40 mph?

A. 265.71 m

B. 438.34 m

C. 345.34 m

D. 330.78 m

260. Traffic travels at 65 mi/hr around a banked highway curve with a radius of 3000 feet. What barking angle is necessary such that friction will not be required to resist the centrifugal force?

A. 3.2 deg

B. 2.5 deg

C. 5.4 deg

D. 18 deg

261. Determine the angle of the super elevation for a 200 m hi-way curve so that there will be no slide thrust at a speed of 90 kph.

A. 19.17 deg

B. 17.67 deg

C. 18.32 deg

D. 20.11 deg

262. The inclination of ascend of a road having an 8.25% grade is _______.

A. 4.72 deg

B. 4.27 deg

C. 5.12 deg

D. 1.86 deg

263. A cyclist on a circular track of radius r = 800 feet is traveling at 27 fps. His speed in the tangential direction increases at the rate of 3 fps^2. What is the cyclist’s total acceleration?

A. 2.8 fps^2

B. 3.1 fps^2

C. 3.8 fps^2

D. 4.2 fps^2

264. A concrete hi-way curve with a radius of 500 ft is banked to give lateral pressure equivalent to f = 0.16. For what coefficient of friction will skidding impend for a speed of 60 mph?

A. µ >0.360

B. µ <0.310

C. µ >0.310

D. µ <0.360

265. What force is necessary to accelerate a 30,000 pounds railway electric car at the rate of 1.25 ft/sec^2, if the force required to overcome frictional resistance is 400 pounds?

A. 1565 pounds

B. 1585 pounds

C. 1595 pounds

D. 1575 pounds

266. A car weighing 40 tons is switched to a 2 percent upgrade with a velocity of 30 mph. if the train resistance is 10 lb/ton, how far up the grade will it go?

A. 1124 ft on slope

B. 2024 ft on slope

C. 1204 ft on slope

D. 1402 ft on slope

267. A car moving at 70 km/hr has a mass of 1700 kg. What force is necessary to decelerate it at a rate of 40 cm/s^2?

A. 4250 N

B. 0.68 N

C. 680 N

D. 42.5 N

268. An elevator weighing 2,000 lb attains an upward velocity of 16 fps in 4 seconds with uniform acceleration. What is the tension in the supporting cables?

A. 2,150 lb

B. 2,495 lb

C. 1,950 lb

D. 2,250 lb

269. A body weighing 40 lb starts from rest and slides down a plane at an angle of 30 deg with the horizontal for which the coefficient of friction µ = 0.30. How far will it move during the third second?

A. 19.63 feet

B. 19.33 feet

C. 18.33 feet

D. 19.99 feet

270. A pick-up truck is traveling forward at 25 m/s. The bed is loaded with boxes whose coefficient of friction with the bed is 0.4. What is the shortest time that the truck can be brought to a stop such that the boxes do not shift?

A. 2.35 s

B. 4.75 s

C. 5.45 s

D. 6.37 s

271. An iron column of annular cross-section has an outer diameter of 200 mm and is subjected to a force of 74 kN. Find the thickness of the wall if the allowable compressive stress is 10 MPa.

A. 12.75 mm

B. 12.57 mm

C. 17.75 mm

D. 15.75 mm

272. A force of 10 N is applied to one end of a 10inches diameter circular rod. Calculate the stress.

A. 0.20 kPa

B. 0.15 kPa

C. 0.05 kPa

D. 0.10 kPa

273. A steel tie rod on bridge must be made to withstand a pull of 5000 lbs. Find the diameter of the rod assuming a factor of safety of 5 and ultimate stress of 64,000 psi.

A. 0.75

B. 0.71

C. 0.84

D. 0.79

274. Determine the outside diameter of a hollow steel tube that will carry a tensile load of 500 kN at a stress of 140MPa. Assume the wall thickness to be one-tenth of the outside diameter.

A. 111.3 mm

B. 109.7 mm

C. 113.7 mm

D. 112.4 mm

275. If the ultimate shear strength of a steel plate is 42,000 psi, what force is necessary to punch a 0.75 inch diameter hole in a 0.625 inch thick plate?

A. 63,000

B. 68,080

C. 61, 850

D. 66,800

276. What force is required to punch a ½-inch hole on a 3/8 thick plate if the ultimate shearing strength of the plate is 42,000 psi?

A. 24,940

B. 24,620

C. 24,960

D. 24,740

277. A single bolt is used to lap joint two steel bars together. Tensile force on the bar is 20000 N. Determine the diameter of the bolt required if the allowable shearing stress is 70 MPa?

A. 17 mm

B. 18 mm

C. 19 mm

D. 20 mm

278. What is the stress in a thin-walled spherical shell of diameter D and a wall thickness t when subjected to internal pressure p?

A. S = D/pt

B. S = 4D/pt

C. S = pD/4t

D. S = pD/t

279. Compute the safe wall thickness of a 76.2 cm diameter steel tank. The tank is subjected to 7.33 MPa pressure and the steel material has a yield stress of 215.4 MPa. The factor of safety to use is 3.

A. 1 ½ inches

B. 3.89 inches

C. 4.09 inches

D. 3.96 inches

280. A cylindrical water tank is 8m in diameter and 12 m high. If the tank is to be completely filled, determine the minimum thickness of the tank plating if the stress is limited to 40 MPa.

A. 11.77 mm

B. 13.18 mm

C. 10.25 mm

D. 12.6 mm

281. A water reservoir of 24 m high and 12 mm diameter is to be completely filled with water. Find the minimum thickness of the reservoir plating if the stress is limited to 50 MPa.

A. 24.5 mm

B. 28 mm

C. 21 mm

D. 26 mm

282. The stress in a 90-cm diameter pipe having a wall thickness of 9.5 cm and under a static head of 70 m of water is

A. 325 kPa

B. 32.5 kPa

C. 32.5 MPa

D. 3.25 Mpa

283. A cylindrical tank with 10 inches inside diameter contains oxygen gas at 2,500 psi. Calculate the required thickness in mm under a stress of 28,000 psi.

A. 11.44

B. 11.34

C. 10.60

D. 10.30

284. A solid shaft 48.2 cm long is used for a transmission of a mechanical power at a rate of 37 kW running at 1760 rpm. The stress is 8.13 MPa. Calculate the diameter.

A.30 mm

B. 35 mm

C. 40 mm

D. 50 mm

285. What is the modulus of elasticity if the stress is 44,000 psi and unit strain of 0.00105?

A. 41.905 x 10^6

B. 42.300 x 10^6

C. 41.202 x 10^6

D. 43.101 x 10^6

286. A 2-inch solid shaft is driven by a 36-inch gear and transmits power at 120 rpm. If the allowable shearing stress is 12 psi, what horsepower can be transmitted?

A. 29.89

B. 35.89

C. 38.89

D. 34.89

287. A hollow shaft has an inner diameter of 0.035 m and an outer diameter of 0.06 m. Compute for the torque in N-m, if the stress is not to exceed 120 MPa.

A.4500

B. 4100

C. 4300

D. 4150

288. Compute the nominal shear stress at the surface in MPa for a 40-mm diameter shaft that transmits 750 kW at 1500 rpm. Axial and bending loads are assumed negligible.

A. 218

B. 312

C. 232

D. 380

289. A hollow shaft has an inner diameter of 0.035 m and an outer diameter of 0.06 m. Determine the polar moment of inertia of the hollow shaft.

A. 1.512 x 10^-6 m^4

B. 1.215 x 10^-6 m^4

C. 1.152 x 10^-6 m^4

D. 1.125 x 10^-6 m^4

290. What power would a spindle 55 mm in diameter transmit at 480 rpm. Stress allowed for short shaft is 59 N/mm^2

A. 42.12 kW

B. 50.61 kW

C. 96.88 kW

D. 39.21 kW

291. A 30-m long aluminum bar is subjected to a tensile stress of 172 MPa. Find the elongation if E = 69,116 MPa.

A. 0.746 m

B. 0.007 m

C. 6.270 mm

D. 7.46 cm

292. A steel wire is 4.0 m long and 2 mm in diameter. How much is it elongated by a suspended body of mass 20 kg? Young’s modulus of elasticity for steel is 196,000 MPa.

A. 1.123 mm

B. 1.385 mm

C. 1.374 mm

D. 1.274 mm

293. A steel wire is 6 m long hanging vertically supports a load of 2000 N. Neglecting the weight of the wire, determine the required diameter if the stress is not to exceed 140 MPa and the total elongation is not to exceed 4 mm. E = 200,000 MPa

A. 3.4 mm

B. 4.4 mm

C. 4.26 mm

D. 5.4 mm

294. A copper rolled wire 10 m long and 1.5 mm diameter when supporting a weight of 350 N elongates 18.6 mm. Compute the value of the Young’s modulus of this wire.

A. 200 GPa

B. 180.32 GPa

C. 148.9 GPa

D. 106.48 GPa

295. A cylinder of diameter 1.0 cm at 30°C is to be slid into a hole on a steel plate. The hole has a diameter of 0.99970 cm at 30°C. To what temperature the plate must be heated? Coefficient of linear expansion for steel is 1.2 x 10^-5 cm/°C.

A. 62°C

B. 65°C

C. 48°C

D. 55°C

296. An iron steam pipe is 200 ft long at 0°C. What will its increase in length when heated to 100°C? Coefficient of linear expansion is 10 x 10^-6 ft/°C

A. 0.18 ft

B. 0.12 ft

C. 0.28 ft

D. 0.20 ft

297. A simple beam 10 m long carries a concentrated load of 200 kN at the midspan. What is the maximum moment of the beam?

A. 250 kN-m

B. 500 kN-m

C. 400 kN-m

D. 100 kN-m

298. a beam supported at both ends and carrying a uniformly distributed load:

A. has its maximum bending moment at the supports

B. has its maximum shear at the center of the beam

C. has its maximum shear at the supports

D. has uniform shear throughout the length of the beam

299. A simply supported beam 10 m long carries a uniformly distributed load of 20 kN/m. What is the value of the maximum shear of the beam due to this load?

A. 250 kN

B. 100 kN

C. 1000 kN

D. 500 kN

300. A simply supported beam, 10 m long carries a uniformly distributed load of 20 kN/m. What is the value of the maximum moment of the beam due to this load?

A. 10,000 kN-m

B. 5,000 kN-m

C. 2,000 kN-m

D. 250 kN-m

Complete List of MCQs in General Engineering and Applied Science per topic